Preparation of injectable N-acetyl glycol chitosan/poloxamer composite hydrogel for drug release

Poloxamer is a thermo-sensitive polymer that can form gel at a concentration of 15.0%(mass fraction, the same as below)-30.0%.In order to decrease the gelatinization concentration and improve drug release properties of poloxamer at body temperature, thermo-sensitive N-acetyl glycol chitosan/poloxamer composite hydrogel was prepared by complexing N-acetyl glycol chitosan with poloxamer 407 (GC/P407).The structure, thermo-sensitivity, mechanical properties, morphology and in vitro drug release properties of GC/P407 were characterized by FT-IR, tube inverting method, rheometer, SEM and UV-vis spectroscopy. The GC/P407 solution shows reversible thermo-sensitive sol-gel transition behavior, and the sol-gel transition temperature is well controlled in the range of 25-37℃ by regulating the ratio of GC/P407, which shortens the gelation time and the gelatinization concentration(6%) of poloxamer 407 at body temperature. GC/P407 composite hydrogel, which has a highly porous three-dimensional structure with pore size of